#define _CRT_SECURE_NO_WARNINGS 1
#include <stdio.h>
int main()
{
	int n, sum;
	float m;
	scanf("%d", &n);
	sum = n * 95;
	if (sum >= 300)
	{
		m = sum * 0.85;
		printf("%.3lf\n", m);
	}
	else printf("%d\n", sum);
}